Noninvasive Assessment of the Autonomic Nervous Tone in Angina Pectoris: An Application of Digital Plethysmography with Auditory Stimuli

To assess the relationship between autonomic nerve activity and the anginal attack, we examined the daily variation of the autonomic tones employing digital plethysmography with auditory stimuli, and also tested the daily variation of exercise capacity. Thirteen of 45 cases (28.9%) of spontaneous angina, excluding Prinzmetal's angina, complained of typical chest discomfort or pain especially in the morning. They manifested an augmented level of the autonomic nerve activity and positive stress testing. The remainder did not demonstrate these abnormal findings in the morning. For the 13 cases, calcium antagonists were given orally immediately after awakening. This resulted in the complete relief from chest discomfort or pain. These findings suggest that an autonomic imbalance plays an important role in the pathogenesis of this type of anginal attack. Thus, the estimation of the daily variation of autonomic nervous tone would be valuable for the diagnosis and treatment of angina pectoris.